Understanding Potential Dietary Drivers of Longevity Across Countries

Introduction

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Describe the datasets you are using, their sources, and any relevant information about the variables included.

Theoretical Focus

Methodology

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Results and Discussion

Plot 1: Countries by Mean Life Expectancy

Plot 2: World Map of Categorized Countries

Plot 1 illustrates life expectancy for countries in the top 10, middle 10, and bottom 10 categories. The accompanying map (Plot 2) geographically locates countries from these three groups. Hovering over the dots on the map or the bars in the chart reveals details for each country, such as the country name, its average life expectancy, and the average caloric intake.

From the bar chart, we observe that Japan leads in life expectancy, followed closely by South Korea, Spain, and France. Noticeably, the gap in life expectancy between the countries in the top and middle categories is relatively small. There is a more significant decline in life expectancy when we compare the life expectancy of countries from the middle group with the bottom group. The countries in the bottom category are predominantly located in Africa, particularly near the equator or in southern regions. In contrast, the middle group of countries includes nations from Asia, Africa, and Latin America, reflecting a more geographically diverse mix.

The countries from the top category are more dispersed, covering Europe, the Middle East, East Asia, and Oceania. Upon first inspection, it becomes evident that the countries in the top category are primarily from the developed world, while the middle category includes less developed countries, and the bottom category comprises the least developed nations.

Plot 3: Change in Life Expectancy 2015-2021

To get a closer look at the developments of life expectancy between 2010 and 2021, let’s consider plot 3. Each line in the chart represents one country, and hovering over it displays details such as the country name and specific data points. The plot shows that countries from the top and middle categories have relatively similar life expectancy, while there is a bigger gap to the countries in the bottom category.

Notably, life expectancy has generally risen over the last decade for countries in all three categories. However, a sharp drop is visible in 2020, which studies suggest may be attributed to the COVID-19 pandemic. According to Cao et al. (2023), global life expectancy declined by an average of 1.8 years due to the pandemic, with Latin America being the most affected region.

The impact of the pandemic is more pronounced in middle-category countries, where the drop in life expectancy was larger than in the top-category countries. This may be due to the varying levels of access to healthcare during the pandemic, though this is speculative and requires further investigation. In contrast, the countries in the top category countries experienced a less significant decline, perhaps because of better access to healthcare.

The gap between the middle and bottom countries is relatively large. While both groups have seen improvements in life expectancy over the years, the bottom-category countries remain far behind. Only three countries of the bottom group —Somalia, Lesotho, and the Central African Republic—experienced a notable decline during the pandemic.

This plot shows that life expectancy has risen globally over the past decade, the effects of external factors such as the COVID-19 pandemic have caused noticeable disruptions, particularly in less developed nations. These trends highlight the importance of addressing healthcare inequities, especially in the wake of global crises.

Plot 4: Change in Caloric Intake 2010-2021

Next, when considering caloric intake, we see that countries in the top 10 life expectancy group also have the highest caloric intake, followed by the middle 10 countries, with the bottom 10 countries ingesting the least (plot 4). From this, a possible initial relationship emerges: countries with higher life expectancy also tend to consume more calories.

However, when examined more closely, it becomes evident that the caloric intake for the top and middle countries is rising steadily, but at different rates. The middle countries show a sharper increase in caloric intake, which may reflect their improving economic and healthcare conditions. In contrast, the bottom 10 countries show a slight decline in caloric intake over the years, even as their life expectancy rises. This counterintuitive trend suggests that while caloric intake plays a role in life expectancy, other significant factors must also be at play.

From these initial observations, we can condense three main points:

  • Countries in the top 10 life expectancy group have had a relatively stable life expectancy since 2010, with only a slight drop during the COVID-19 pandemic. These countries also consume the most calories across the observed period.

  • The middle group, while still developing, shows progress: both life expectancy and caloric intake have risen since 2010. Their caloric intake is the second highest among the three groups, and their life expectancy is gradually approaching the levels seen in the top category.

  • The bottom 10 countries also show an increase in life expectancy over the years, but their caloric intake has declined slightly. Despite consuming fewer calories, these countries have managed to improve their life expectancy, indicating that factors beyond nutrition—such as healthcare access and disease prevention—could be contributing to these gains.

Plot 4: Nutritional Profile Comparison

Conclusion